The biggest fear of urban composting is the smell. But a healthy compost bin smells like a damp forest floor, not garbage. Here is how to keep it that way:
Bad odors are caused by anaerobic bacteria thriving in wet, nitrogen-rich environments. For every cup of food scraps (greens), add two cups of shredded paper or dry leaves (browns).
Anaerobic means "without oxygen." Ensure your balcony bin has ventilation holes to allow oxygen to circulate and dry out excess moisture.